抄録
From the study of fossils the present status of mammals in Japan is considered to have appeared since the Diluvian epoch of Quaternary. Most of the present mammals in Japan show close relation to those of the Asiatic Continent and the distribution pattern shows that there occurred animal interchange between the both areas in ancient times. Prototype of mammalian fauna of Hokkaido seems to have been constructed up to Post-glacier period after the isolation of Hokkaido from the neighbouring areas. At present, mammalian fauna of Hokkaido includes 19 sp. and 34 subsp. belonging to 34 genera, 14 families, 6 orders (see Table 1). The characteristic of mammalian fauna of Hokkaido is consisted in a mixed existence both of northern cold zone species and of southern temperate zone species including some great sphere ones. There are many marine animals which are rare in the Main Island. The existence of many northern cold species in Hokkaido and South-Kuriles shows close faunal relation to Sakhalin and Primorskii. Three genera of the vole, namely Clethrionomys, Aschizomys and Eothenomys; two species of the shrew, namely Sorex minutissimus and Sorex hosonoi; two species of the squirrel, namely Sciurus vulgaris and Sciurus lis; and two species of the hare, namely Lepus Brachyurus and Lepus timidus are very similar respectively in all aspects. However, no phylogenetic study of the animal has been made, though the matter is very interesting. The occurrence of Crocidura dsinezumi, Sorex minutissimus and Ochotona hyperborea in Hokkaido is particular. Their ecological and zoogeographical studies are necessary. More species of mammals in Kuriles may be added in future.
